In the manufacturing process of an LCD, the entire mother panel is cut into single panel units after a cell-assembly process. As illustrated in FIG. 1, a single panel unit includes an array substrate 1 and a color filter (CF) substrate 2 arranged opposite to each other. One end of the array substrate 1 is exposed and used for bonding a circuit board or circuit boards 3.
FIG. 2 is a sectional view of FIG. 1 along a dotted line PP′. In the bonding process of the circuit board 3, the array substrate 1 makes direct contact with a base table 4, and an anisotropic conductive film (ACF) 5 is adopted to bond the circuit board 3 on a bonding area of the array substrate 1. In the manufacturing process, a high-temperature hot press head 6 is adopted for the hot pressing of the circuit board 3; the ACF 5 is fused by application of heat; and the thermal heat 6 is removed after maintaining for a predetermined time. The ACF 5 is cured, so that the circuit board 3 can be firmly fixed on the array substrate 1.
In the hot pressing process, the heat conducting path is: hot press head 6→circuit board 3→ACF 5→array substrate 1→base table 4. The temperature difference between the hot press head 6 and the base table 4 is large, so that the expansion amount of the circuit board 3 making contact with the hot press head 6 will be greater than the expansion amount of the array substrate 1 making direct contact with the base table 4. Thus, in the subsequent process of curing the ACF 5, the circuit board 3 and the array substrate 1 are cooled, so that the shrinkage amount of the circuit board 3 will be greater than the shrinkage amount of the array substrate 1, and hence the bending or warping of the circuit board 3 and the array substrate 1 as illustrated in FIG. 3 can be produced. The bending will result in the change of the distance between the array substrate 1 and the color filter (CF) substrate 2 at the periphery of the bonding area, so that the display color at the periphery of the bonding area will change to a certain degree. Thus, Mura phenomenon can be caused, and hence the image display quality can be affected.